用php写的一个HTTP下载类 晴

jed , 2006-10-11 15:28 , 代码编程 , 评论(0) , 阅读(4145) , Via 本站原创 | |
在php中,下载http资源比较常用的一种做法就是用 file_get_contents 这个函数,但这函数无法获得http头的信息,会给一些应用带来不方便,因此我写了一个http下载类来解决这个问题,测试感觉速度和file_get_contents相差无几。


<?
/*=======================================
// 织梦Http下载类
// 织梦之旅 www.dedecms.com
=======================================*/
class DedeHttpDown
{
var $m_url = "";
var $m_urlpath = "";
var $m_scheme = "http";
var $m_host = "";
var $m_port = "80";
var $m_user = "";
var $m_pass = "";
var $m_path = "/";
var $m_query = "";
var $m_fp = "";
var $m_error = "";
var $m_httphead = "" ;
var $m_html = "";
//
//初始化系统
//
function PrivateInit($url)
{
  $urls = "";
  $urls = @parse_url($url);
  $this->m_url = $url;
    if(is_array($urls))
    {
    $this->m_host = $urls["host"];
    if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];
   
    if(!empty($urls["user"])){
    $this->m_user = $urls["user"];
    }
   
    if(!empty($urls["pass"])){
    $this->m_pass = $urls["pass"];
    }

    if(!empty($urls["port"])){
    $this->m_port = $urls["port"];
    }
   
    if(!empty($urls["path"])) $this->m_path = $urls["path"];
    $this->m_urlpath = $this->m_path;
   
    if(!empty($urls["query"]))
    {
    $this->m_query = $urls["query"];
    $this->m_urlpath .= "?".$this->m_query;
    }
 }
}
//
//打开指定网址
//
function OpenUrl($url)
{
 //重设各参数
 $this->m_url = "";
 $this->m_urlpath = "";
 $this->m_scheme = "http";
 $this->m_host = "";
 $this->m_port = "80";
 $this->m_user = "";
 $this->m_pass = "";
 $this->m_path = "/";
 $this->m_query = "";
 $this->m_error = "";
 $this->m_httphead = "" ;
 $this->m_html = "";
 $this->Close();
 //初始化系统
 $this->PrivateInit($url);
 $this->PrivateStartSession();
}
//
//获得某操作错误的原因
//
function printError()
{
 echo "错误信息:".$this->m_error;
 echo "具体返回头:<br>";
 foreach($this->m_httphead as $k=>$v)
 { echo "$k => $v <br>\r\n"; }
}
//
//判别用Get方法发送的头的应答结果是否正确
//
function IsGetOK()
{
 if( ereg("^2",$this->GetHead("http-state")) )
 { return true; }
 else
 {
  $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."<br>";
  return false;
 }
}
//
//看看返回的网页是否是text类型
//
function IsText()
{
 if(ereg("^2",$this->GetHead("http-state"))
  && eregi("^text",$this->GetHead("content-type")))
 { return true; }
 else
 {
  $this->m_error .= "内容为非文本类型<br>";
  return false;
 }
}
//
//判断返回的网页是否是特定的类型
//
function IsContentType($ctype)
{
 if(ereg("^2",$this->GetHead("http-state"))
  && $this->GetHead("content-type")==strtolower($ctype))
 { return true; }
 else
 {
  $this->m_error .= "类型不对 ".$this->GetHead("content-type")."<br>";
  return false;
 }
}
//
//用Http协议下载文件
//
function SaveToBin($savefilename)
{
 if(!$this->IsGetOK()) return false;
 if(@feof($this->m_fp))
 { $this->m_error = "连接已经关闭!"; return false; }
 $fp = fopen($savefilename,"w") or die("写入文件 $savefilename 失败!");
 while(!feof($this->m_fp)){
  @fwrite($fp,fgets($this->m_fp,256));
 }
 @fclose($this->m_fp);
 return true;
}
//
//保存网页内容为Text文件
//
function SaveToText($savefilename)
{
 if($this->IsText()) $this->SaveBinFile($savefilename);
 else return "";
}
//
//用Http协议获得一个网页的内容
//
function GetHtml()
{
 if(!$this->IsText()) return "";
 if($this->m_html!="") return $this->m_html;
 if(!$this->m_fp||@feof($this->m_fp)) return "";
 while(!feof($this->m_fp)){
  $this->m_html .= fgets($this->m_fp,256);
 }
 @fclose($this->m_fp);
 return $this->m_html;
}
//
//开始HTTP会话
//
function PrivateStartSession()
{
 if(!$this->PrivateOpenHost()){
  $this->m_error .= "打开远程主机出错!";
  return false;
 }
 if($this->GetHead("http-edition")=="HTTP/1.1") $httpv = "HTTP/1.1";
 else $httpv = "HTTP/1.0";
 fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
 fputs($this->m_fp,"Host: ".$this->m_host."\r\n");
 fputs($this->m_fp,"Accept: */*\r\n");
 fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n");
 //HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束
 if($httpv=="HTTP/1.1") fputs($this->m_fp,"Connection: Close\r\n\r\n");
 else fputs($this->m_fp,"\r\n");
 $httpstas = fgets($this->m_fp,256);
 $httpstas = split(" ",$httpstas);
 $this->m_httphead["http-edition"] = trim($httpstas[0]);
 $this->m_httphead["http-state"] = trim($httpstas[1]);
 $this->m_httphead["http-describe"] = "";
 for($i=2;$i<count($httpstas);$i++){
  $this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
 }
 while(!feof($this->m_fp)){
  $line = str_replace("\"","",trim(fgets($this->m_fp,256)));
  if($line == "") break;
  if(ereg(":",$line)){
   $lines = split(":",$line);
   $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]);
  }
 }
}
//
//获得一个Http头的值
//
function GetHead($headname)
{
 $headname = strtolower($headname);
 if(isset($this->m_httphead[$headname]))
  return $this->m_httphead[$headname];
 else
  return "";
}
//
//打开连接
//
function PrivateOpenHost()
{
 if($this->m_host=="") return false;
 $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10);
 if(!$this->m_fp){
  $this->m_error = $errstr;
  return false;
 }
 else{
  return true;
 }
}
//
//关闭连接
//
function Close(){
 @fclose($this->m_fp);
}
}

?>



这个类的使用方法:

下载网页


<?
$httpdown = new DedeHttpDown();
$httpdown->OpenUrl("http://www.dedecms.com");
echo $httpdown->GetHtml();
$httpdown->Close();
?>



如果下载图片并保存,可以用


<?
$httpdown = new DedeHttpDown();
$httpdown->OpenUrl("http://prato.bokele.com/0/0/399/bGluMi5qcGc=.jpg");
echo $httpdown->SaveBin("test.jpg");
$httpdown->Close();
echo "<img src='test.jpg'>";
?>



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